Satoyuki Tanaka

On the Analysis of Stress Concentration Problems Using Wavelet Galerkin Method (1st Report, Mathematical Formulations and Treatments on External Boundaries)

In this paper, discussions on B-spline wavelet Galerkin method are presented for its mathematical formulations and numerical implementations. Scaling function and wavelet are used as the trial and the test functions in Galerkin formulation. These basis functions have the so called multiresolution property. B-spline scaling function and wavelet have simple forms and are easy to integrate and differentiate. However, there are some difficulties in dealing with external boundaries. They are due to the loss of linear independence of the basis functions. To circumvent these problems, we introduce the boundary scaling functions/wavelets or eliminate particular basis functions that can be expressed by the linear superposition of the other basis functions. Numerical results are presented for the problems of tensile plate with a circular hole.

Finite Element Seismic Response Analysis of a Reinforced Concrete Pier with a Fractured Fine Tetrahedron Mesh

A seismic response analysis of a reinforced concrete (RC) pier has been undertaken using seismic waves recorded at the Takatori station during the southern Hyogo perfecture earthquake in 1995 in Japan. Distinguishing characteristics of this analysis are as follows. First, the RC pier has been modeled using the finite element method with a solid mesh. The analysis model has been generated using tetrahedral elements with node connectivity, not only in the concrete but also in the reinforcement steel. Also, an analysis has been undertaken on fracture treatments in the concrete. Using PDS-FEM, a system of suitable fractures in the concrete resulting from the seismic event can be simulated. Ultimately, a finite element model is established with a fine tetrahedron mesh with about 20 million elements. We calculate a seismic response analysis using the K computer at the RIKEN Advanced Institute for Computational Science, and compare that result with a seismic experiment in E-Defense to confirm the computational approach.